Used as a reference standard in environmental testing laboratories to calibrate analytical instruments for the detection and quantification of polychlorinated biphenyls (PCBs) in soil, water, and biological samples. It helps ensure accurate measurement of PCB contamination, which is critical for regulatory compliance and environmental monitoring. Commonly employed in gas chromatography (GC) and mass spectrometry (MS) analyses due to its stable composition and known concentration. Also used in research studies assessing the persistence, bioaccumulation, and toxicity of chlorinated organic pollutants.